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DEPARTMENT OF HEALTH & HUMAN SERVICES

National Institute for Occupational Safety and Health

Division of Compensation Analysis and Support

This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution.

Memorandum

DCAS External Memorandum 

Division of Compensation Analysis & Support 

To: Metals and Controls (M&C) Special Exposure Cohort (SEC) Working 

Group 

From: Peter Darnell, DCAS Health Physicist

Subject: SC&A Review of the SEC00236 M&C Petition Evaluation Report 

Date: February 22, 2018 

The following update is provided for the M&C SEC Working Group. NIOSH received SC&A’s review 

of the M&C ER on February 12, 2018. NIOSH will provide a revised SEC ER to accommodate to 

SC&A’s findings and observations. Currently, NIOSH is reviewing bioassay data from the M&C 

remediation contractor (Creative Pollution Solutions – CPS), finalizing a subsurface soil exposure 

model, and following up with interviewee reviews of interview transcripts. NIOSH anticipates 

completion of the revised ER upon completion of these activities. NIOSH plans no new data captures or 

interviews before completing its revision of the ER. 

The current revision of the ER states that for the class under evaluation, NIOSH found no part of the 

class for which it cannot estimate radiation doses with sufficient accuracy. Fundamentally, the SEC 

review agrees with NIOSH’s assessment. However, the SC&A review noted several findings and 

observations. The remainder of this memorandum briefly addresses SC&A’s findings and observations 

with the expectation that the revision to the ER will fully address the concerns raised in the SC&A 

review.

Finding 1: Internal exposures associated with subsurface maintenance and repurposing activities in 

Building 10 during the residual period should be explicitly included in the ER. NIOSH should not 

assume that there is sufficient conservatism inherent in the internal dose reconstruction methods 

employed in the ER to account for these exposures. 
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This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution.

NIOSH response

In October 2017, NIOSH (with SC&A’s participation) conducted interviews with personnel 

knowledgeable of site activities during the residual period. Upon review of that data, NIOSH agrees that 

the subsurface exposure provided in the current ER requires improvement to reflect more accurately the 

actual exposure potential during the residual period. The model currently in development should, with 

exception of calculations, be approved by the end of February 2018. 

Finding 2: NIOSH incorrectly transcribed some of the Landauer film badge dosimetry reports and 

incorrectly calculated annual 95th percentile external penetrating doses to workers in the residual period. 

NIOSH response

NIOSH will correct this in the revised ER.

Finding 3: NIOSH incorrectly calculated annual 95th percentile beta skin doses to workers in the 

residual period. 

NIOSH response

NIOSH will correct this in the revised ER.

Observation 1: SC&A suggests that a more appropriate approach to deriving the chronic airborne 

concentration of uranium from resuspension during the residual period would be to use the average 

value for the swipe data (i.e., 12.3 dpm/100 cm2) and a resuspension factor of 1E-5/m. This would result 

in chronic uranium inhalation rates that are about 2 times higher, but well within a reasonable range for 

these types of exposures, given the available data. 

NIOSH response

NIOSH is reviewing this suggestion and will provide an updated approach for accounting for 

resuspension in the revised ER. 

Observation 2: The distinction between production and non-production workers should be better defined 

in the ER. After discussions with NIOSH, it was determined that the production worker group is 

intended to refer to workers who may have entered production areas. This includes construction trade 

workers, including, but not limited to, those listed in the ER. Additional text adding clarity to this point 

would ensure that this distinction is consistently applied to workers.

NIOSH response

Currently, NIOSH plans on a simplified approach. All M&C workers in the Facilities Construction and 

Maintenance Services Organization (Facilities) or Production Machine Operators/Helpers and 

Production Repair & Maintenance (R&M) organizations having access to, and work within production 

areas are considered to have potential for subsurface exposure. The revised ER will assign dose as 

appropriate using the calculated doses and a derived stay time in the work area. NIOSH will also assign 

resuspension dose to all workers following the TBD-6000 model. 
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This is a working document prepared by NIOSH’s Division of Compensation Analysis and Support (DCAS) or its contractor for use in discussions 

with the ABRWH or its Working Groups or Subcommittees. Draft, preliminary, interim, and White Paper documents are not final NIOSH or 

ABRWH (or their technical support and review contractors) positions unless specifically marked as such. This document represents preliminary 

positions taken on technical issues prepared by NIOSH or its contractor. NOTICE: This report has been reviewed to identify and redact any 

information that is protected by the Privacy Act 5 USC §552a and has been cleared for distribution.

Observation 3: NIOSH should consider adopting the approach used in the ER for Carborundum and the 

ER and technical basis document for General Steel Industries (GSI) for deriving ingestion doses during 

the residual period.

NIOSH response

When estimates of air concentration values are available, the OTIB-009 approach is the preferred 

approach. When air concentration data is not available, but surface contamination values are, NIOSH 

uses NUREG /CR-5512 . 

Observation 4: Exposures experienced by High Flux Isotope Reactor (HFIR) workers cannot be used “as 

supporting evidence to validate the bounding method used in Section 7 of this report” as stated on page 

24 of the ER. 

NIOSH response

NIOSH will consider this observation and modify the revised ER as appropriate. 

Observation 5: SC&A is concerned that it may be inappropriate to use external dosimetry data collected 

during the last year of Atomic Weapons Employer (AWE) operations as the basis for bounding the 

external doses during the residual period. 

NIOSH response

AWE fuel was removed at the end of M&C site operations. However, a sizable amount of HIFR fuel 

remained. In its current approach, NIOSH does not deplete external source term for doses over site 

residual period, making doses assigned in the ER more conservative than that described by this 

observation. NIOSH agrees that the source term over time should deplete and will provide new 

calculations in the revised ER to maintain agreement with depletion of external doses. 

[Signature on File]

Peter Darnell, CHP, RRPT 

Division of Compensation Analysis and Support